Observed climate trends 15. Trend in global average surface temperature The mean global surface temperature has increased by about 0.3 to 0.6°C since the late 19th century and by about 0.2 to 0.3°C over the last 40 years. 16. Precipitation changes: trend over land from 1900 to 1994 Precipitation has increased over land at high latitudes of the Northern Hemisphere, especially during the cold season. Decrease in precipitation occurred in steps after the 1960s over the subtropics and the tropics from Africa to Indonesia. 17. Sea level rise due to global warming Over the last 100 years, the global sea level has risen by about 10 to 25 cm. Source: United Nations Environment Programme / GRID-Arendal
